The ns Manual (formerly ns Notes and Documentation)1 - NM Lab at ...

double uniform (double a, double b) – return a number sampled from a uniform distribution on [a, b]double exponential (void) – return a number sampled from an exponential distribution with mean 1.0double exponential (double k) – return a number sampled from an exponential distribution with mean kdouble normal (double avg, double std) – return a number sampled from a normal distribution with thegiven average and standard deviationdouble lognormal (double avg, double std) – return a number sampled from a lognormal distribution withthe given average and standard deviationExample/* create new RNGs */RNG arrival (23456);RNG size;/* set the RNGs to the appropriate substream */for (int i = 1; i < 3; i++) {arrival.reset_next_substream();size.reset_next_substream();}/* print the first 5 arrival times and sizes */for (int j = 0; j < 5; j++) {printf ("%-8.3f %-4d\n", arrival.lognormal(5, 0.1),int(size.normal(500, 10)));}Output161.826 506160.591 503157.145 509137.715 507118.573 49625.2 Random VariablesThe class RandomVariable provides a thin layer of functionality on top of the base random number generator and thedefault random number stream. It is defined in ~ns/ranvar.h:class RandomVariable : public TclObject {public:virtual double value() = 0;int command(int argc, const char*const* argv);RandomVariable();225